Queen of the Underworld
by EvelynGreenx
Summary: What if Clary and Jace's plan had failed? What if they were all stuck in the demon dimension? And what if Sebastian was only just warming up? Clary has the ultimate decision to make - fight for those who she loves or accept her darker nature and embrace what Sebastian has to offer. There is only one thing for sure; the war has only just begun.
1. Welcome to Hell

-This story starts from the scene which Clary ascends the thrown in the demon dimension but things take a little turn for the worst...-

**Disclaimer: I do not own any of the characters in the Mortal Instruments.**

Rising from the throne, Clary avoided the betrayed looks from her friends, ashamed of the decision she had chosen. But there was no other way, Clary was positive of that. Her hands trembled by her side, completely aware that tears were threatening to fall. She would not let that happen, she was braver than that. Clary was the reason they were all in this situation so it would appear feeble and selfish if she were to show her true emotions. She was vaguely aware of Sebastian's voice, the cruel malice that was evident in the tone but she daren't lift her head or the reality would sink in. Staring intently at a cracked tile on the floor, an icy chill enveloped her. Clary's breathing became laboured as she stealthily reached her hand around her back and gripped the hilt of her sword. Feeling the cool metal against her skin, the tension seemed to ease and her shoulders set.

Keeping her head bowed, she flicked her eyes up for only an instant to survey the surroundings. Sebastian was only a few feet in front of her, waving his arms erratically, a huge grin set onto his face. Clary glanced towards her friends to find them all watching Sebastian, pure hatred and distain painted in their features. Jocelyn was positioned the closest, her hands balled into fists at her side but there was a look of sorrow deep in her eyes. Clary knew that her mother blamed herself for all that had happened but she had only wished for a young boy that had never existed. Luke stood very close to her, his eyes continuously brushing over Jocelyn to ensure she hadn't lost it all. Just behind, Isabelle remained poised, her whip glistening as her fingers lingered waiting for an opportunity to strike. Her dark hair hanging wildly around her shoulders, emphasising the glimmer of fury in her eyes. Simon seemed immobile, appearing even paler than what his vampire traits should allow. Shock written across his face, his lips slightly apart. Alec and Magnus stood slightly to the side of Simon. Alec the stoic shadow hunter he had trained to be and Magnus looking utterly confused, his eyebrows knitted together.

Clary's eyes drifted across her friends and family and then froze. There he was. Standing away from the others, his hands steady at his side, his jaw set firmly with his dark golden hair hanging in front of his eyes, obstructing further view. Her heart sank further in her chest, her hands became clammy on the grip of the sword. Clary longed to forget about everything and just run towards him, throwing her arms around him and whisper soothing words. Just as Clary was about to give up all hope and pull her eyes away, Jace lifted his head, only minutely enough so that no one else would notice but Clary did. Their eyes met and Clary's breath hitched. Even in a life or death situation Clary couldn't help how he made her feel. They stared at each other for only a moment but it felt like a lifetime. His eyes quickly glanced towards Sebastian before they met hers again as he carefully nodded his head, expertly, so as not to be seen.

That was the sign she needed. It was now or never. Looking back at Sebastian, adrenaline coursed through Clary's veins. She felt the electricity sizzling through her fingers were it touched the hilt of the blade. Her heartbeat soared as her eyes narrowed, focusing on her target. Without a second thought Clary lunged forward, a scream ripping from her throat. Time seemed to slow down around her. Drawing the blade, she swung it with an almighty force just as Sebastian turned to face her. Surprise was evident on his face but it was quickly replaced with an uncontrolled anger. Clary lashed out, aiming for the middle of Sebastian's chest but he was much quicker, his reflexes kicking in. Dodging out of range, Sebastian righted himself but before he could make a move Clary was on him. Swinging her sword Clary struck again, delivering blow after blow but Sebastian was too fast. Artfully avoiding each attack until he found an opening. Just as Clary lifted her sword once again, Sebastian was in front, landing a blow to her stomach.

"No," Jace cried out and began to advance towards Sebastian. Sebastian merely lifted his hand, stopping Jace in his tracks. A threat that needn't be spoken. Clary stumbled backwards, the breath leaving her body in one agonising moment. Steadying herself, Clary looked up at Sebastian, a smirk painted upon his lips, delight shining in his eyes. Summoning all of her energy, Clary charged forward but she was too slow. Sebastian side stepped Clary and efficiently wrapped his arm firmly around her neck whilst picking the sword easily from her grasp. A gasp escaped Clary's throat as she was held tightly against Sebastian. Her eyes grew wide as the unwelcome realisation dawned on her; it had failed.

Clary's eyes darted towards Jace, searching his face for any recognition of another plan but there was nothing. His eyes looked strained, his mouth slightly agape as he fixed his gaze on hers. Clary could see the defeat in his golden depths and she felt her body instinctively constrict. Sebastian's breath was hot and moist against her ear causing her to recoil but there was nowhere for her to go. Clary didn't have to see him to know the smirk that would be dominating his face or the look of superiority to be gleaming in his eyes. She could almost feel his devilish grin against her cheek.

"Please tell me my dear brother and sister that this wasn't all of your plan? If so I am hugely disappointed." The pleasure was clear in Sebastian's tone. Clary grimaced as his words hung in the silent air that seemed to be suffocating. She closed her eyes, too exhausted to face the stares of everyone around her. Her body sagged against Sebastian as the fight seemed to die inside of her. Clary had lost all hope, there was nothing that could be done to stop Sebastian. She had given up.

Clary felt a cold, slim finger caress her cheek and then gently tug at her chin. Slowly she opened her eyes to find herself staring into Sebastian's bottomless, black depths. He bent his head closer to hers and Clary couldn't help the gasp that escaped her lips as Sebastian's lips brushed against hers, sending an icy shiver down her spine. His lip quirked at the corner upon seeing how uncomfortable this made her and still he pulled her closer so his breath mingled with hers. His eyes bore into hers and she felt as though she was falling into the oblivion.

"Welcome to hell Clarissa."


	2. Possession

**Disclaimer: I do not own any of the characters from the Mortal Instruments series.**

Jace's breath constricted, his hands balling instinctively into fists. It took everything he had not to throw himself across the room and rip Sebastian's filthy fingers away from Clary. Jace could feel his heartbeat soar as Sebastian leaned in closer to her and his whispered words seemed to echo off the walls. Jace's blood ran cold as his muscles seemed to freeze at the intensity of Sebastian's tone. Jace now found that he was not that far away from the two but yet he may as well have been a million miles away; there was nothing he could do.

Jace watched from afar as Clary tried to break free from Sebastian's grasp but it was all in vein. Even if she had the chance, there would be nowhere left for them to go. Sebastian's gaze drifted over Jace, violating him as Jace was reminded of a time when it was so simple for Sebastian to brush his thoughts. A ghost of a wink appeared on Sebastian's face and Jace could see how he revelled in the outcome. A loud cracking sound pulled them all from the sick and twisted reverie. Sebastian darted his eyes towards the window to Alicante and his manic laugh seemed to fill the air.

Bile rose in Jace's throat as he watched in astonishment a single crack spread like wild fire across the middle of the window, obscuring the images of those fighting. The window creaked, a signal that it couldn't hold itself up much longer and the moment it fell, that would be it. The realisation hit Jace like a ton of bricks. There had always been the hope that they would all make it home and look back at this one day and consider it a fond but dangerous memory. Jace had assumed that they would get out of this, just like they always did. Now that he was faced with the reality he was speechless. His whole childhood was through that window and now it was being stripped away from him. Jace's eyes diverted away, unable to continue watching the end.

Clary could not take her eyes away from Jace. She could see the pain laced in his eyes as his jaw hung loose. Clary hated to see Jace this way, alone, defenceless and frightened. What's more she knew he didn't drop his barricades for anyone so Sebastian must have succeeded in getting under his skin. Hearing another crack at the window sent despair circling through Clary and she couldn't bare to look in its direction. She watched as Jace tore his gaze away from the window and something inside of her snapped. Summoning all of her strength she flipped her head back to hear the satisfying crunch of Sebastian's nose. Startled by her sudden attack, Sebastian's grip loosened slightly and Clary took this as her chance. Spinning round in his arms, she brought her knee up to collide with his stomach efficiently knocking the breath out of him. Sebastian wheezed and gripped his stomach in pain.

Clary took off running at a pace towards the mirror, watching the cracks increase the closer she seemed to get. She was almost there, just a little bit further and then she may be able to do something to stop it. Just as Clary neared the window, her fingertips stretched outward, she was so close to Alicante. The cracks from the window multiplied, sending the shimmering shards crashing down in a storm of ice. Clary felt the horror slice through her as the edge of a jagged shard left a cut along Clary's cheek, increasing the pain inside of her. But Clary barely felt it. Her lips felt cold and dry, her limbs had gone completely numb as she watched the image of Alicante fade from the numerous broken pieces of glass. Along with it went her last hope. The last light diminishing in Clary's eyes.

Sinking to her knees, Clary carefully picked up a disregarded shard and studied it, willing to be able to see the tiniest spark of life. She wished that there still could be a way. But there was nothing. No ray of sun, no twinkle of a star, no familiar faces smiling; nothing. Clary held the glass tighter, the rugged edges biting into her exposed flesh, blood mixing with the cold metal. Clary shut her eyes, trying desperately to block out the world around her. So many emotions were running through her, tearing at her very soul. Clary bit down on her tongue, the taste of blood and metal filling her mouth.

"It's over Clarissa," a voice whispered to Clary.

Turning her head to glance up, Sebastian was looming over her, his expression guarded. His mouth was set in a firm line as his raven eyes flicked to the cut on her cheek. Clary noticed how they softened slightly; if only for a moment.

"Why have you done this?" Clary ground out, trying to muster as much hatred and loathing into her words.

Sebastian knelt in front of her, wicked contempt flashing in the depths of his heartless eyes. Lifting his hand, he ran a gentle finger along the gash on Clary's cheek as she winced away from his touch. Clary's heart froze at the sudden contact and she could not pull her eyes away from his; it all seemed like a sardonic game of chess. As he withdrew his hand, Clary couldn't help but notice the crimson liquid dripping from his finger. Due to everything happening she hadn't realised how deep the glass shard had penetrated. Sebastian continued to stare in fascination at his finger, his eyebrows drawing together.

"I have done this for us. So you can take your rightful place by my side and we can rule this world together," Sebastian stated as though it was a known fact. His conviction sent a wave of nausea over Clary.

"I will never serve by your side," Clary spat, lacing her words with venom, her eyes aflame with vengeance.

Sebastian chuckled softly to himself, humour dancing in his black depths. He turned his gaze on her and fear gripped her like a vice. Sebastian's stare was intense and full of dark promises, his lips quirked into a smirk, his teeth flashing like knives beneath.

"It wasn't a request, my dear sister," Sebastian snickered, lifting his blood soaked finger as his tongue snaked out to lick the length. His devilish glare held Clary captive, invading her very soul.

"You're mine now."


	3. Submission

**Disclaimer: I do not own any of the characters involved in the Mortal Instruments.**

Clary pulled her eyes away from Sebastian, turning away from the malevolent intent deep within their depths. He was so close that she could feel his breath stir the strands of hair hanging free at her cheek. She still felt his eyes boring into her, her anxiety spiking. Clary leant backwards, unable to move completely but wanting to put as much distance between them. She looked towards the floor, wishing it would just swallow her up and save her from this nightmare.

A sudden laugh sliced through the thickening silence. Clary glanced up in surprise, entirely expecting to see Sebastian the source but this quickly turned to confusion. Jace stood at the base of the steps, humour and mirth mixed in his golden depths as the irrepressible laughter bubbled from his lips. Jace's eyes sliced across the distance, connecting with Sebastian in a challenge.

"She'll never be yours." The humour instantly vanished from his features and was replaced with a vengeance that made his golden eyes burn with intensity. His hands curled into fists at his sides, his feet evenly spaced, ready for anything that was about to happen.

Clary looked from Jace to Sebastian and her blood turned as she saw the flicker of annoyance in his eyes. Sebastian was growing impatient, Clary was sure of it. Before Sebastian could respond, Clary's natural instincts took over. Clary rose to her feet, astonishing herself with the grace she seemed to muster. She felt her leg buckle slightly but she remained firm, exuding authority. She kept her face expressionless, something she had learned from Jace. Staring straight at Jace, his hard exterior had softened slightly at seeing Clary before him; but she didn't even flinch.

"I don't need you to defend me Jace. I can handle myself." Inwardly she recoiled at the severity in her tone but she didn't let the façade slip. This was the only way she knew how to protect those she loved. She witnessed the hurt that flashed across his face but it was soon replaced with his generic arrogance. In her mind Clary thanked him for not showing how weak he was but she couldn't help the nag that told her that he might just not care.

"I think we've been through enough to safely admit that might not be true," Jace jeered. Clary knew Jace could give just as good as he got. Clary's heartbeat hammered in her veins as her mind whirled. She could only think of one way that she could possibly protect Jace and her friends but it could make them hate her in the process. Surely it was worth it if she could defend them, wasn't it?

Without thinking too much, Clary tore her eyes away from Jace , one last slip of innocence as she allowed him to see into her soul. Turning away, she stalked to the centre of the raised platform, feeling the eyes of everyone around her following her every move. She tried to put as much confidence as she could into her walk as she held her head up high, afraid to look down in case she would fall. Reaching the two thrones she stood before her own, risking a side long glance at Sebastian who seemed to be frozen as he watched her in appreciation. Nausea wafted over her at the thought. Clary glanced away quickly, focusing her attention on Jace. His stance defensive and cold, something she never imagined she would see aimed at her.

"Jace, it's over. Why can't you accept that? Sebastian won." The words felt like acid on Clary's tongue as they dripped from her lips.

"I will never accept something that has yet to be proven," Jace remarked. He smoothly uncurled his fists and opted instead to fold his arms across his chest, appearing a little too standoffish for Clary's taste. Something inside of her snapped at seeing his cool exterior, desperate to see what he was feeling beneath the surface.

"Look around you Jace," Clary exclaimed. "Accept the reality of the situation because if this is what winning looks like then you can count me out." The words scratched at Clary's throat as her own words rang clear in her ears, her own screams echoing off the walls. Clary breathed heavily from the outburst, her thoughts raced as she felt the tension thicken in the room. She could almost hear the shocked gasps from those around her but Jace seemed as though he barely heard her, remaining an emotionless statue. Clary felt sick at the roughness of her words but she couldn't let the others know her true intentions. Jace simply regarded Clary with a bleak expression, his eyes dull and flat. His mouth was drawn in a tight line as he continued to stare into her eyes.

"This is not over Clary. Don't you think for a second that I will bow down without a fight." A challenge seemed to sparkle in his eyes and she didn't like the idea of Sebastian and Jace going head to head, she wouldn't be entirely sure who would win. Clary dropped her gaze and heaved a sigh, the burden lying heavy on her chest.

"And what if there is nothing left worth fighting for?" Clary whispered, momentarily dropping her front and allowing her true emotions to show but before she could rebuild the borders Jace stepped forward, only a single step but the shortened distance was welcome. He met her gaze and held her eyes levelly.

"There is always something worth fighting for," Jace spoke gently. His hushed tone made it feel more personal despite the audience that was listening in. For a moment longer, she enjoyed the Jace that stood before her; the glimmer of sweat shining on his forehead as his passion consumed, the wrinkle in his forehead at the intensity of his words, the crease at the corner of his eyes as his golden depths strained for her to understand.

Clary had already decided. Inhaling a deep sigh, she straightened herself, hoping to achieve the posture of someone with power and authority. Casting a swift look back towards Sebastian, Clary nodded slightly and his eyes lit up with excitement. Ice seemed to run through her veins but she remained poised. Facing forward, she looked straight ahead, unwilling to meet the eyes of her family and friends.

Slowly Clary took her place, nestling in her future position. She sat down on the throne, the frame engulfing her petite body. Resting her hands on the arms of the throne she ran them carefully over the intricate details carved into the décor. Gathering all of her strength, she lifted her chin so that she was looking down at those below her. Narrowing her eyes, her lip curled back over her teeth she stared straight into Jace's golden eyes. Her brain saying _'I'm sorry' _but her mouth trained to perfection.

"Bow before your Queen."


	4. City of Ruins

Clary remained calm, despite the anxiety that was ripping her apart. Her gaze was locked with Jace's in a wicked game of checkers. Her words seemed to bound off of him without even a scratch to the surface. Jace remained immobile with the cool exterior of an ice sculpture, carved to perfection. His eyes were unreadable, the guard was up and it took all of Clary's might not to tear them down.

A sound of clapping broke through the moment, disrupting Clary's train of thought. She whipped her head to the side to find Sebastian predatorily making his way towards her, his black, bottomless eyes trained on her. His mouth was lifted in a smirk as the clapping slowly diminished.

"My, my Clary. Who would have thought you'd have it in you?" Appreciation and admiration laced his tone as he came to a stop beside Clary. Sebastian slowly lifted his hand, deliberately making Clary aware of this, and delicately brushed a strand of hair behind her ear. Instead of cringing away from his touch, she stayed transfixed, refusing to allow Sebastian to break her.

Stroking a single finger down her arm, he laced his icy fingers through hers, bringing her hand to his lips. Sebastian held her gaze as his hot breath brought goose bumps to the surface of the exposed flesh.

"My Queen," Sebastian breathed and with that he brought her hand towards his lips and placed a gentle, loving kiss on her sensitive skin.

Sucking in a sharp breath, Clary felt dread begin to fill her as she watched Sebastian bow before her, head bent so that his blonde hair was covering his eyes. Clary felt as though she was playing with fire, it was a very risky game that she was trying to master and she still wasn't entirely sure whether Sebastian was one step ahead of her.

Before she could analyse the situation too much, Sebastian lifted his head and flashed Clary with a quick smile before he rose to his feet and faced the others. For the first time in a while she allowed herself to meet the gazes of her friends. They still remained in the places she had first seen them, immovable. Their eyes followed Sebastian's movements with suspicion, seemingly unaware of Clary's presence.

Clary's gaze brushed Simon's and a pang of guilt shot through her. His eyes softened slightly but the betrayal was clear in their depths. Unlike Jace, Simon was an open book, he had never been good at disguising his true emotions and in this instant it broke Clary's heart. She longed to throw herself across the distance and assure him that she was still the same old Clary; his best friend. She watched as a swarm of emotions crossed Simon's pale complexion; confusion, anger, but most of all hurt. Simon tore his eyes away from Clary's and stared down at the floor, Clary's heart tightening at the cold nature of his actions. She had slight hope that him, over everyone else, may have understood why she was doing this but she now realised that he may not be able to see through her act.

A firm hand on her shoulder, broke Clary from her reverie as her eyes shot up to collide with Sebastian's. His touch sent a cold wave over her skin as he turned his head away from her, clearing his throat.

"Bow before your Queen." Alarm sliced through Clary at Sebastian's words and she wondered if he was toying with her. Shooting a pleading look at Sebastian she tried to reason with him but his eyes were trained expertly on Jace's. She could see the metaphysical war they were engaged in and it was evident that Sebastian was winning. Standing up abruptly, she raised her palms and calmed her nerves.

"There is no need for that," Clary reasoned, drifting her eyes briefly over her friends. She felt Sebastian move next to her, a quiet chuckle resounding from his throat so that only she could hear.

"On the contrary Clarissa, they need to understand your authority and power." Sebastian caressed her cheek with slow, gentle fingers. "They're no longer your friends but your subordinates," Sebastian resolutely whispered. Clary froze at the word 'subordinate' and she felt her universe shift and her world falling out of balance. Had she taken it too far? Heat radiated from her form as her hands slightly shook at her sides. Her mind raced with other possibilities but she came up with the inevitable.

Clary looked up at Sebastian to find a grin firmly fixed on his lips, mischievous delight clear in the light in his eyes. Fearing her words may deceive her she minutely nodded at Sebastian and lowered her eyes in submission. Gripping the top of her arm rather harshly, Sebastian marched towards the edge of the steps with Clary in tow. Her blood ran cold as her worst fears were coming true.

Halting at the edge of the steps, Sebastian's grip never faltered on her arm, the pain numbing. Clary kept her gaze lowered, fearing if she looked up she might crumble. Inside she was falling apart, a city of ruins. Clary felt backed into a corner with no other options, her hands were tied.

"Bow," Sebastian barked causing Clary to flinch at the aggression in his tone. His voice carried through the vast expanse of the room and wrapped around Clary in a vice. Casting a sideways glance, Clary noticed the humour had left Sebastian's face. Instead was the cold, harsh mask of a boy with no soul. Clary had wished things were different. If only Sebastian hadn't been brought up on the dark side, taught the ways of evil or loved in the wrong way. What if Sebastian had been raised with Clary? Under the same loving roof, filled with happiness and laughter. Clary pictured the young boy her mother had long since cried after, the life shining in his eyes, the genuine smile gracing his lips.

Looking at him now Clary only felt despair for what Valentine had done to him. The icy, calculating boy in front of her was as foreign to her as her own father. The demeanour of a warrior, the stance of a leader but with the intentions of the devil. She searched his coal eyes, hoping for a glint of faith but the only thing she could see was the remains of dead dreams.

A blur of movement caught Clary's attention and her heart almost stopped. Feeling her throat go dry she couldn't fathom the words to express her astonishment. Catching Simon's eye, his face was stern and grave, far from the carefree boy she called her best friend. Never breaking eye contact, he sunk to one knee, head slightly bowed. Clary's breath constricted, her chest tightening. With one last look of despair, Simon bent his head, his arm resting on his knee. Clary couldn't believe what she was seeing. Tears pricked behind her eyes but she blinked them away, she couldn't afford to risk Sebastian seeing her vulnerable.

Simon remained bowed before her. Her eyes flicked to the others, looking at Simon in astonishment, more so than anyone; Isabelle. Before Clary could react, she watched in utter shock as Magnus followed suit, falling to one knee, his head bowed. Alec watched him, his mouth slightly agape but shortly after, shaking his head he repeated his actions. Surely enough, a domino effect started. Isabelle, Jocelyn and Luke sunk to one knee and Clary hated seeing the ones she loved showing weakness.

One by one they fell until one was left standing. Clary's gaze shifted until she was confronted with a pair of smouldering golden eyes. She could see the flame of determination rising in their depths. Clary was grateful for Jace's streak of stubbornness but she feared for what may face him if he doesn't do as Sebastian commands. Standing with his feet shoulder width apart he remained like a statue, his hands balled into fists at his sides. Defiance written across his face.

"Jace," Isabelle fiercely whispered, surprising Clary to hear her speak up. However, it barely broke through Jace's façade. Ignoring her insistence he did not move apart from the tilt of his chin.

"Never." Jace's eyes bore into Sebastian's, challenging his next move. Clary held her breath, terror smothering her. She felt as though she may feint as annoyance sparked in Sebastian. The electricity flickered between them, the intensity penetrating her very soul.

Before her mind could register what was happening, Sebastian stalked down the steps, his face struck with fury. Smoothly withdrawing a seraph blade with the expertise of a trained shadow hunter, he held it to Jace's throat. The glistening metal casting shapes across his neck. Gripping Jace's arm from behind, the blade dug in slightly. A drop of crimson liquid staining the metal.

"This isn't a game Jace. There are no winners here." With that Sebastian pushed Jace up the steps, stumbling marginally. They came to a stop just in front of Clary and she felt as though she would explode. Too many emotions swirled inside of her, consuming her very being.

Jace's eyes would not meet hers as he cast them down, avoiding her completely. Clary could only stand there as she watched her world ripping at the seams. Her fingers twitched at her side as she had to restrain from reaching out and touching him. Removing his blade from Jace's throat, Sebastian placed his hand on Jace's shoulder and began to push, forcing Jace to buckle under the pressure.

"I said bow," Sebastian emphasised the last word, dragging the vowel out and turning it in to a deep growl.

Jace met Clary's gaze and the force in his eyes was overwhelming. She tried to find his true emotions but Jace was not giving anything away, his features a mask of stone. Clary wanted scream at him, hit him, anything for him to show the smallest bit of feeling. Clary willed Jace to understand, her eyes softening slightly in hope that he may follow. This was not the case. Jace's expression did not change as he regarded her blankly.

Against Jace's will, he was forced to one knee, Sebastian looming over him and just like that the divide was created.

There was no turning back.


End file.
